JPS6241658A - Medical and sanitary non-woven fiber absorbent and its production - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a nonwoven fibrous absorbent body for use in the medical and/or sanitary field. The invention further relates to a method for manufacturing such an absorbent body.

[Conventional technology and problems]

In the medical and hygiene field, absorbent planar structures are required as surgical wound dressings, dressings or cotton balls. In this case, the use of woven cotton gauze as a structure has the disadvantage that it adheres to the wound during wound treatment. Furthermore, the ability of this cotton gauze to absorb and absorb wound secretions is insufficient.

In order to reduce the adhesion to the wound, it has been used to coat wrinkle-free pressure bandages or wound plasters with gauze in the middle with a hydrophobic synthetic fiber layer of a woven fabric layer.

European Patent Application No. 77,034 describes an absorbent wound dressing comprising two layers of covering at least on the wound side and having a superabsorbent material in the center.

The central layer of the two layers is made of a non-woven fibrous material with high sealing properties, and the outer layer is made of a woven polypropylene fabric with a lattice structure. Such woven fabrics, which are not non-woven materials, can be
It facilitates the migration of wound secretions into the absorbent material without causing blockage of these openings. The high sealing fibrous nonwoven material joining the outer lattice layer with the absorbent layer thereby approaches the wound very closely. Note that the edges of these two-layer covers can be welded to the absorbent pad.

However, by joining these two outer layers, the possibility of folding the planar structure is compromised. That is, such planar structures are subject to high stresses at the folds of the fabric cover and often tend to break. However, collapsibility is often necessary to increase capacity and improve absorption.

Therefore, when implementing the above technique, very capacious, non-collapsible absorbent bodies must be used. As a result, handling is limited and manufacturing costs are significantly increased.

Furthermore, the need to pre-manufacture the polypropylene woven layer prior to manufacturing the wound cover also results in increased costs.

Covers that include non-weldable nonwoven material coatings are prohibited because they require polymeric binder dispersions and because they contain leachable additives that are physiologically unacceptable for medical treatment.

French Patent Publication No. 2,536,432 manufactures a perforated, binder-free nonwoven material from rayon stable fibers with a primarily abrasion resistant surface, the fibers being bonded together by a very high pressure water jet. 1 illustrates a hydraulic perforation device and method that can be entangled. This product is characterized by an approximately 50% higher absorption capacity for aqueous solutions compared to woven cotton gauze.

However, the energy cost of obtaining bonding with high-energy water streams is very high. Furthermore, since this product contains a considerable amount of rayon staples on its surface,
Tends to stick to wounds.

[Problem to be solved by the invention]

The object of the invention is that it can be used in many ways, especially in the medical and sanitary fields, and that its absorbency corresponds to that of perforated rayon table or cotton non-woven materials, but does not contain any binders and is It is an object of the present invention to provide an absorbent body which does not have any fuzz, has abrasion resistance, does not adhere to wounds, and can be folded several times as necessary without causing damage. This would provide an absorbent body with advantages not hitherto achievable with known medical absorbent bodies.

A further object of the invention is the technical use of water flow coupling and
It is also an object to provide a cheap and simple method of manufacturing such an absorbent body, which involves the use of a layer of non-woven material/textile cover and does not require binders for fixation.

[Means for solving problems]

This task consists of at least one absorbent fibrous layer and at least one outer fibrous layer of hydrophobic non-woven material covering this at least on the wound side, with through-holes distributed over the entire surface of the absorbent body. In the non-woven fiber absorbent material for personal use and hygiene, at least 80% of the hydrophobic fiber layer consists of synthetic composite filaments containing low melting point and high melting point components, and the absorbent fiber layer and the hydrophobic fiber layer are gradually intermingled. The invention is solved by an absorbent body which is characterized in that the perforated part does not contain substantial entanglement of fibers and that the entire absorbent body is cured only by composite filaments and without binders. This absorbent manufacturing method is a manufacturing method in which water is mechanically perforated through the composite using a slit-type water injection nozzle and a hole type, and at least 80% of the hydrophobic fiber layer is made of a synthetic material containing low-melting point and high-melting point components. using a composite filament, then perforating with a water stream of low impact energy that does not result in substantial fiber entanglement in the perforated area, and then removing moisture by drying at a temperature above the melting point of the low melting point component. is characterized in that the composite is cured under pressure without the addition of a binder and optionally heat-smoothed on one or both sides.

The fibrous layer of the absorbent layer and the fibrous layer of the hydrophobic cover intermingle and transition into each other at the boundary area between the two. That is, since these layers are superimposed thin-layer coatings and are heat-bonded under pressure, they no longer have a distinct boundary layer. The products according to the invention can therefore no longer be called laminates, but fiber layer composites.

According to the invention, the hydrophobic outer layer contains up to at least 80% synthetic composite fibers (composite filaments) comprising a high melting point component and a low melting point component.

Other fibers may be uniform synthetic filament fibers, optionally containing small amounts of cellulose fibers.

The absorbent fibrous layer generally consists of well-known cellulosic fibrous materials, optionally mixed with other fibers. In this case, it is advantageous to mix in the binding fibers that are to be cured. It is advantageous to include up to 30% of composite filaments of the same type as in the hydrophobic cover in order to produce cheaply and to provide expandability in the absorbent layer. The binding fibers also serve to bond the absorbent layer and the outer layer(s).

According to another particularly preferred variant of the absorbent article according to the invention, the absorbent layer comprises, together with cellulose fibers, polyvinyl alcohol fibers which can be softened in hot water, or entirely of polyvinyl alcohol which can be softened in hot water. Consists of fibers.

This embodiment has the advantage that binding fibers can be omitted, since each layer is self-adhesive under the conditions mentioned above, and that such fibers have a significantly higher aqueous solution-accepting capacity than cellulose fibers. have.

In another advantageous embodiment of the absorbent article according to the invention, the absorbent layer preferably consists only of several layers of cellulose paper. This embodiment is particularly preferred for use in the hygiene field. Cellulose is relatively inexpensive and has very strong bonds, even when dry and under high stress.

In this case as well, the addition of binding fibers can be omitted.

The absorbent body according to the invention has through holes distributed over its entire surface. However, according to the present invention, this absorbent body does not have intertwining of fibers in its pores which are useful for fixation. This absorbent composite is heat-cured primarily by the low melting point component of the composite filament, and its hydrophobic outer side(s) has a non-fluffy structure.

The finished product weight of the absorbent body is preferably in the range of 30 to 50 g/m2, and the weight proportion of the hydrophobic outer layer(s) should be determined as small as possible from the standpoint of foldability and absorbency. It is. For example, fiber count 1, 7
In the case of d tex, it should be set at 6 g/m''.

The hydrophobic surface of the absorbent body can be textured or smooth. The former properties are suitable for wound cleansing products, the latter properties for wound dressing products (as little adhesion to the wound as possible).

In one particular embodiment of the absorbent article according to the invention, at least one fiber layer comprises crimped polypropylene fibers. Such fibers provide mechanical hardening of the non-perforated areas both in the fiber plane and in a plane perpendicular to the fiber plane. In this case, the degree and direction of this hardening can be easily changed by changing the number of crimped fibers and the fiber orientation. Such absorbents are characterized by an increased liquid-receiving capacity due to the increased volume, especially after several folds.

The method for producing an absorbent article according to the invention consists first of all in placing at least two fiber layers one on top of the other. One of the layers includes conventional absorbent fibers and the other layer includes hydrophobic thermoplastic composite filaments. In this case, at least 80% of composite filaments are used as the outer hydrophobic fiber layer(s). This composite filament contains high melting point and low melting point components. These fibrous layers are then exposed to a thin, low energy stream of water that produces essentially no fiber entanglement, only hydraulic perforation.

However, drilling with low energy water jets alone does not provide fiber entanglement or abrasion resistant surfaces, so additional curing is required. According to the present invention, the absorbent body can be manufactured without using a binder, since curing takes place only by the composite filament.

To perforate fiber composites (stacked),
Water is injected over the entire width of the material with sufficient pressure to allow the elongated slit nozzle to perforate it. Suitable devices for this purpose are, for example, French Patent Publication No. 5.536,
No. 432 describes this in detail.

arranged around the fibrous layer to move with the fibrous layer;
A "water curtain" is formed on the perforated plate.

The underlying fiber layer is perforated by the penetrating water according to the pore structure of the perforated plate without substantial fiber entanglement. It is preferable that the open surface of the perforated plate be as large as possible. This is because the longitudinal and transverse webs of the pores are formed with a very large volume, so that capillary spaces are created in the finished absorbent body for receiving other liquids. Furthermore, these high volume "webs" increase the abrasiveness of the surface, which is particularly useful for wound cleansing and cosmetic applications.

Following perforation, water is removed by drying, and the planar structure is heated and cured at a temperature above the melting point of the low melting point component of the composite filament. The hydrophobic surface is optionally smoothed later.

As composite filaments, fibers with a hexagonal structure and also conjugated (joined side by side) fibers can be used.

To increase strength and reduce adhesion to the wound, the outer surface of the composite filament of the dry-cured absorbent body can be heat-smoothed by known calendering methods. If a fairly large volume of the product is desired, smoothing is carried out in the gap between two finishing rollers with relatively low compaction pressure. By changing the gap between the rollers,
The volume of the absorber can be changed arbitrarily.

In contrast, a high degree of drapability or foldability is obtained by not performing full-scale welding. In this case, the engraving depth of the roller should be chosen not to be too small in order to keep the absorbent body in one piece.

In one particular embodiment of the invention, one or several of the fiber layers are mixed with polyester fibers that are highly shrinkable in hot water or steam. The perforated and wet planar structure thus shrinks during the drying process. Mechanical hardening occurs due to the associated compression of the fiber composite along the longitudinal and transverse webs, and in part due to the longitudinal and transverse orientation of the fibers. The degree of shrinkage in the machine and transverse directions is primarily dependent on the fiber orientation and the shrinkage fiber content. After drying is completed, hardening of the fibers occurs again by heating above the melting point of the low melting point component of the filament fibers. The above-mentioned fiber orientation is associated with an increase in the volume of the absorbent body, which is particularly evident by the increased liquid-accepting capacity after one or several folds.

In order to obtain high production rates and thus good economics,
The fiber layers are mostly longitudinally oriented.

The very low lateral strength associated with this can be easily increased, if necessary, by stacking each layer at right angles to the layer immediately below. Such an arrangement is particularly advantageous for absorbents in the surgical field where high tear resistance is required.

In order to avoid yellowing or other thermal damage to the inner absorbent fiber layer, the low melting point component can be activated (melted) in a purposeful manner at a temperature that the absorbent fibers can still withstand without damage. . Such composite filaments consist, for example, of polyethylene terephthalate/polyethylene (or polypropylene).

Fibers containing polypropylene components are furthermore stable to steam sterilization. Therefore, this form should be used preferentially for folded compresses that are sterilized in an autoclave. For good foldability, the count of any fibers should be as low as possible, and such fibers should have as low a stiffness as possible.

〔Effect of the invention〕

The products according to the invention can be used in many ways, both in the medical field and in the hygiene field. This means that the absorbent body has an absorbency that is at least comparable to known perforated fleece layers, is lint-free and very abrasion-resistant, even though it does not contain any binder additives.

The openings in the outer layer formed by the welding of the fibrous components are irregular but sufficiently large to ensure a reliable transfer of secretions into the absorbent layer. This generally non-woven absorbent body provides a similar effect to known two-layer non-woven/textile covers. However, the present invention does not require the use of such a fabric and does not suffer from the aforementioned disadvantages associated therewith.

Adhesion to the wound is effectively prevented by providing a hydrophobic fiber covering layer, optionally with a smoothed shape. Furthermore, it is possible to fold this absorbent body several times without damaging it and heat seal it in this state into a very bulky absorbent body.The outer layer contains thermoplastic fibers. For this reason, the single-folded, two-piece embodiment can be welded to the absorbent pad along the edges, thereby ensuring that undesirable protrusion of fibers from the absorbent layer on its sides is avoided. can.

The method of the present invention enables inexpensive and rapid continuous production of highly effective fibrous absorbents. In principle, 2 Lance Patent Publication Specification-1 No. 2.53 Fi, No. 432
), but the present invention uses low energy! - [Water Curtain-1
It is important to perform hydraulic perforation due to This procedure is suitable for recuring 1 coζ without binder, IX
Fibers commonly used in the medical, sand, and sanitary fields ■1 composite +, 1' c: Meets all of the imposed requirements.

[Actual example]

The fourth embodiment of the present invention and drawing IA, 4λ and C2 will be further explained.

Practical example 1- A staple fiber nonwoven material (composite) having a three-layer structure is manufactured from a card machine of several types. The two proximal layers are 1. 40 mm polyester/polyethylene bicomponent fiber 7 in count 1 and 7 dte and cut length respectively
g/m", the absorbent fiber layer placed in the middle 6.' is composed of 80% viscose I/.-Constelpule of 3 dtex and cutting length 40 mm and the above composite filan, /1.20 Composed of 4%.

The sludge-sol fiber composite of 7 layers (having 1z / II + 2) with a weight of 4 (1z / II + 2) is combined with +1iff of hydraulic perforation; S:, ice is t! It Mist Zuruko, I-'
I'm so wet. Go. Use 1: The hole treatment included a rectangular hole with a width of 1.4n+m and a length of 2.51 size in the flow direction. The width of the 97 blades was 0.50 mm without exception. That person's open surface accounted for 55% of the total area of the perforated plate.

Thin water flow force from the slit nozzle ~)-n (approximately 60μm
) will collide with the hole at a pressure of about 10 bar.) is 2. After perforation, 160'c 1. 'Oiko i/i! i
Let it dry and harden in the surrounding air.
Therefore, the volume is large, the absorbency is strong, and 1. A friction-resistant medical absorbent material has been produced. This is not foldable no matter what condition it is in! However, it has a significantly higher water-accepting capacity than cotton gauze or commercially available water-binding products.

Figure 1 shows the absorber according to Example 1 (r, 21:; !c), where hydrodynamic perforation by low-energy water flow 2. I will show you how to create a hollow hole without substantially increasing it.

7.1-1 (cross-sectional view of the absorber according to Example 1) is
After assembly, perforation and curing of the non-woven material composite, some (hydrophobic) fibrous layers at the top or bottom partially penetrate into or become entangled with the absorbent middle layer. For the case ・′), the complex of 1 and ゛ has a pure layer state r)(,
There is no j5, □Tate (male II official &, :, there is a j7).

Large%ヱExample 2), and 11111Example 1 r,,':yo-,゛(:One side of the bonded absorber 4.,10!j''(blank,,□,1 big, smooth Na 2, Boliteto U”nor 1st ゛ko〕, jl
, ・N' laminated fabric 6, smoothed with pads 1 and 2. 、゛、
Therefore, '6.1 color has a smooth surface that does not contain cotton <1j', (,,,,,6-0) in that this material G' does not stick to the wound, Water flow bonding17 was significantly lower than folded gauze and gauze substrates based on nonwoven materials.

[Brief explanation of the drawing]

Figure 1 is a plan view (enlarged 20 times) of an absorbent body according to the invention, and Figure 2 is a cross-sectional view (20 times enlarged) of a three-layer absorbent body of the invention.
], 00x magnification). Figure 2 Procedural amendment written format) % formula % 1. Indication of the case Japanese Patent Application No. 1983-138035 2. Name of the invention Medical and sanitary non-woven fiber absorbent material and its manufacturing method 3. Case of the person making the amendment Relationship with Patent applicant Karl Freudenberg 4, agent 1-3 Nakai Building (6389), Nihonbashi Yokoyama-cho, Chuo-ku, Tokyo
Patent Attorney Kaoru Furuya 5, Date of amendment order: August 26, 1985 (shipment date) 6. Column for brief explanation of drawings of the specification subject to amendment and drawings (1) Specification 2
Page 1, lines 18-20, “Figure 1...-” was corrected as follows.

Claims (1)

[Scope of Claims] 1. An absorbent body comprising at least one absorbent fiber layer and at least one outer fiber layer made of a hydrophobic nonwoven material covering the absorbent fiber layer at least on the wound side, with through holes distributed over the entire surface of the absorbent body. In the nonwoven fiber absorbent material for medical and sanitary use, at least 80% of the hydrophobic fiber layer is composed of synthetic composite filaments containing low melting point and high melting point components, and the absorbent fiber layer and the hydrophobic fiber layer are mixed. 1. An absorbent article characterized in that the perforated portion does not contain substantial entanglement of fibers, and that the entire absorbent article is cured solely by composite filaments and without a binder. 2. The absorbent article according to claim 1, wherein the absorbent fiber layer contains at least one type of binding fiber. 3. Claim 1 or 2, characterized in that the absorbent fiber layer contains up to 30% of said composite filaments.
Absorber described in section. 4. The absorbent article according to claim 1 or 2, wherein the absorbent fiber layer contains polyvinyl alcohol fibers that can be softened in hot water. 5. The absorbent article according to claim 1 or 2, wherein the absorbent fiber layer consists of only a cellulose layer. 6. The absorbent article according to any one of claims 1 to 5, wherein at least one fiber layer includes crimped polyester fibers. 7. At least one absorbent fiber layer and at least one hydrophobic fiber layer covering it are arranged in an overlapping manner, and then this composite is mechanically perforated with water by means of a slit-shaped water injection nozzle and a hole shape. , a method for producing a non-woven fiber absorbent material for medical and sanitary use, in which a synthetic composite filament containing at least 80% of low-melting point and high-melting point components is used as a hydrophobic fiber layer, and then a substantial portion of the fiber is formed in the perforated portion. Drilling with a water stream of low impact energy that does not result in entanglement, followed by removal of moisture by drying, and forming the composite under pressure at a temperature above the melting point of the low melting point component without the addition of a binder. A method characterized by curing and optionally heating and smoothing one or both sides. 8. The method of claim 7, wherein the absorbent fibrous layer includes bonded fibers. 9. The method according to claim 7 or 8, characterized in that polyester fibers capable of shrinking in hot water or steam are added to at least one fiber layer, and the shrinking takes place simultaneously with drying. . 10. According to any one of claims 7 to 9, characterized in that only one or several cellulose layers are used as absorbent fiber layers, which are moistened before the hydraulic perforation. Method described.